Fishing tool



Patented Aug. 24, 1937 PATENT GFFICE FISHING TOOL Weldon C. Erwin, Huntington Park, Calif., as-

signor to John Grant, Los Angeles, Calif.

Application June 5, 1935, Serial No. 25,069

12 Claims.

This invention has to do generally with oil well iishing tools, and particularly with tools of this character which operate to dislodge and retain the iish, i. e., the object to be recovered,

I by a suction effect produced by suddenly releasing the well fluid and sand in the vicinity of the fish into a normally empty low pressure chamber within the tool, or within the drill pipe -on which it is lowered into the well.

One of my principal objects is to provide a shing tool of this type whereby preliminarily to drawing in and retaining the fish within the tool, the latter may be operated to cut around and center the fish in proper position for recovery. The invention also has for its object to provide an improved mechanism whereby the low pressure chamber closure may be opened as a result of vertical movement of the suspension means or pipe string, or, more specifically, by

parts of the tool. In the particular form of the invention hereinafter described, and in conjunction with the closure opening mechanism, I have provided means whereby a portion of the drill string load may be brought to-bear on the tool during the preliminary operation of milling around and centering the i'lsh, and releasable means whereby the pipe string weight may be utilized for the purposeof opening the chamber closure. Additional features of the invention have to do with means for maintaining a flow of circulating fluid downwardly through the pipe string to the lower end of the fishing tool, past the low pressure closure and independently of its condition, i. e. regardless of whether it is open or closed.

The above mentioned and various other features and objects of the invention will be clearly understood from the following detailed description, wherein reference is made to the accompanying drawing, in which:

Fig. 1 is a sectional view showing a typical form of fishing tool embodying the invention, and with the charge receiving chamber closed from communication with the well; and

Fig. 2 is a sectional view, showing a variational form of the invention, with the parts in the positions taken after the charge receiving' chamber closure has been opened.

erally indicated at I0, is shown to be lowered into the well bore II on the lower end of the drill pipe or tubing I2 extending to the ground surface. In its preferred form, the fishing tool comprises a body including upper and lower relavirtue of relative vertical movement between Referring rst to Fig. 1, the fishing tool, gentively vertically movable sections I3 and I4, attached to the drill pipe I2 by coupling I5. Upper body section I3 comprises a tubular section I6 threaded at I1 into coupling I5, and forming a normally closed charge receiving chamber 5 I8, pipe I6 being of considerable length in order to form a charge receiving chamber of a capacity sumclent to take in a substantial volume of well fluid, as hereinafter explained'. The lower end of tube I 6 is threaded at I9 into an intermediate section 20 of the upper body portion I3, section 20 in turn being threadedly connected at 2| with the lower section 22 of the upper body portion. n i

Intermediate section 20 has a reduced diameter bore 23 which forms the inlet to the charge receiving chamber I8, and which is normally closed by a suitable closure means, to seal the said chamber against the entry of well liquiduntil the tool is operated to recover the fish. 20 In certain of its aspects, the invention broadly contemplates the provision of 'any suitable type of closure adapted to be opened by movement y of the suspension pipe I2, or byrelative movement between the body sections I3 and I4, to place the charge receiving chamber in communication with the well through the lower body section. In other and more specific aspects, the invention is particularly concerned with the use of a frangible disk-type closure in fishing tools of this type, and a disk breaking means operated by movement of the suspension pipe or relative movement between sections of the tool body.

I have shown the closure for chamber I8 to comprise a frangible member or disk 24 clamped between body shoulder 25 and retaining nut or bushing 26 threaded into the lower end of body section 20. Lower body section I4 includes a tubular member 2'I having an integral, reduced diameter mandrel portion 28 extending upwardly through the lower end of the bottom portion 22 ofthe upper body'section I3. Relative rotation between the two body sections I3 and I4 is prevented by mandrel splines 28a extending through ways 29 in body portion 22. Threaded at 30 on the upper end of the mandrel portion 28 is a disk breaking member 3| preferably in the form of a tube having an upper toothed end 32 adapted to engage and break the disk 24 upon downward relative movement of the upper body section I3, as will presently appear.

Lower body section I4 also includes a iish receiving and retaining means shown typically in the form of a hollow shoe 33 threaded at 34 into the lower end of member 21. If desired, shoe 33 may be provided with a series of cutting teeth 33a in order that the tool may be used to mill around and center the fish within the shoe, prior to and in preparation for subsequently drawing 5 the fish into the interior 35 of the shoe upon opening the low pressure chamber I 8. Suitable means. such. as a plurality of inwardly projecting fingers 36 pivotally mounted at 31 withinthe shoe 33, are provided for the purpose of retaining the fish l after it has been drawn up into space 35.

The normal positions of the parts are as shown in Fig. 1, wherein body section I3 is releasably held in raised position relative to the lower section I4 by releasable means generally indicated at l5 38. It will be understood that the latter may be of any suitable type capable of resisting or preventing downward movement of the upper body section under sufficient load to afford `thenecessary pressure on the shoe 33 t`o effectively mill around and center the fish, but yet capable of being released to permit downward relative movement of the upper body section for the purpose of opening the charge receiving chamber closure. As a typical means 38 for releasably maintaining the body sections in the relative positions of Fig.. 1, I have shown a pair of shear pins 39 projecting from body portion 22 into the mandrel 28 as at 40. Pins 39 will have sufficient resistance to shearing to transmit to the shoe 33 a pressure or load necessary for cutting operations, but will become sheared under at least the entire weight of the drill string, to'drop the upper body section I3 to the disk breaking position of Fig. 2.

Before performing the fishing operationand 35 while the tool is being used preliminarily to center the fish, it is desirable to maintain a circulation r 'of fluid down through the drin string I2 to the vicinity of the shoe 33. It is also desirable, in view of the necessity for maintaining a chamber I8 in 40 closed condition prior to drawing in the fish, that the circulation be maintained around or past the disk 24,I with the latter closed. Circulation may be maintained by providing within chamber I8 a tube 42 terminating at its upper end within coupling I 5, and connecting by way of nipples 43 with pipes 44 extending downwardly at the outside of the body through openings 45 into the interior 35 of shoe 33. Pipes 44 may have a sliding fit within openings 45, or at least -just sufficient clearance to allow upward movement of the shoe 33 relative to the pipes during the diskbreaking operation, withoutbinding.

Fig. 2 shows a variational form of the invention similar in all respects to Fig. 1, except as to the substitution of a body encircling sleeve in place of pipes 44 of Fig. 1, for conducting the circulating fluid from the point of discharge from pipe 42,

into the shoe 33. In Fig. 2, a sleeve 46, placed about the body of the tool, is secured at its lower 80 end 46a, by threading or in any other suitable manner, to the shoe 33, the upper end 46b of the sleeve having a sliding fit with the outside of tubular portion I6 of the upper section I3 of the tool. If desired, packing 4I may be provided Within the 5 upper end 46b of the sleeve to prevent upward leakage of circulating fluid being discharged from pipe 42 through openings 48 into the annular `ace 49within the sleeve 46. 'I'he circulating `uid passes from space 49 downwardly through openings 5I) in the top shoulder oi the shoe into the interior 35 thereof.

In operation, the tool is lowered to the bottom ofthe well and the drill string I2 rotated to cause the .teeth 34 to mill around the lodged ob-` 7'5' ject or sh 5I and center the latter Within the lower end of the shoe. I Ins 39 have sufficient resistance to shearing to enable a substantial pressure or load to be imposed on the shoe, thus enabling the latter to effectively cut around and preliminarily position the fish 5I for recovery. 5 Y

Thereafter, the entire weight of the drill string, or a sufficient portion of itsg weight, is released onto the pins 39 to cause them to shear and the upper body section I3 to move downward, relative to the lower body section I4, to the position' 10 of Fig. 2. As a result of such movement, the f disk 24 is projected down against the upper end -32 of the disk breaking member 3I with sumcient force to rupture the disk and place chamber I6 in communication with the interior 35 ofshoe 15 33 via bores 53 and 54 of member 3| and the mandrel portion 28.

The low pressure chamber I8 thus is suddenly placed in communication with the well, with the result that by reason of the pressure differential, 20 there is induced a sudden rush of well fluid upwardly through the shoe 33 and bores 54 and 53 into the low pressure zone. By reason of the suction effect and high velocity flow of the well fluid upwardly into the low pressure chamber, the fish 25 l 5I is displaced or drawn up into the interior 35 of the shoe past the pivoted fingers 36. After having been drawn into the shoe, the fish is retained against dropping out by the fingers 36, as shown in Fig. 2, and the fish is then recovered by ele- 3.0 vating the tool to the ground surface.

If desired, provision may be made for bleeding air from the linterior of the low pressure chamber I8 by means of an outwardly opening check valve 55 pressed into engagement with its seat 3 56 by means of a' leaf spring 51 attached at 53 to the outside of body portion I6. Ordinarily,

I prefer to allow the charge consisting of well liquid and sand, drawn upwardly into the low pressure Achamber I8 as previously explained, to 40 drain back into the well after the fish 5I has become retained. However, if desired, the charge taken into the low pressure chamber may be trapped therein for removal to the ground surface, by inserting within body portion 20 a check 45 valve 59 which raises to permit the upward flow intol chamber I8, and then seats on shoulder 60 to trap the charge in the chamber thereafter.

At the completion ot the described fishing operation, the pipe string is raised lto bring shoul- 50 der 62 into engagement with lower end 63 ofthedisk breaking member, continued upward movement of the pipe string then elevating the entire tool assembly. In case it should happen that as a result of the sudden release of wellr pressure into the charge receiving chamber I6, the lowerv portion or shoe 33 of the tool becomes sanded, l. e., submerged in a deposit of sand to such an extent as to offer substantial resistance to its removal, extraction of the tool may be facilitated by rotating the shoe, through the splined engagement between the mandrel 28 and the upper body section. The provision for relative longitudinal movement between the body sections I3 c5 and I4 and the engagement between shoulder 62 and 63 affords a further means of loosening the shoe in case it should become stuck in the well, in that by lowering the upper body section to the position of Fig. 2 and then raising shoul- 70 der 62 upwardly into impacting engagement with shoulder 63, a jarring e'ect is produced that acts immediately to. dislodge the shoe.

I claim:

. 1. In a fishing tool of the character described.

the combination comprising a body, means forming a low pressure chamber within the body, a frangible closure below said chamber and adapted to be opened to admit well fluid thereto, suspension means on which said body islowered in the well, means at the lower end of said body and movable vertically relative thereto, forv receiving and retaining a fish to be recovered,

means operable by straight relative vertical -movement between the body and the last mentioned means to open said closure and thereby induce a ow of well uid into said chamber, and means for maintaining a ow of circulating iiuid downwardly through the suspension means and past said closure to the lower end of said body.

2. In a fishing tool of the character described, the combination comprising a body, means forming a low pressure chamber within the body, a frangible closure below said chamber and adapted to be opened to admit well fluid to a low pressure chamber, suspension means on which said body is lowered in the well, means at the lower end of said body and movable vertically relative thereto, for receiving and retaining a fish to be recovered, means operable by straight relative vertical movement between the body and the last mentioned means to open said closure and thereby induce a flow of well fiuid into.said chamber, and means on said body for maintaining a flow of circulating fiuid'downwardly through the suspension means and said low pressurechamber, and past said closure to the lower end of said body.

3. In a fishing tool of the character described, the combination comprising a body, means forming a low pressure chamber within the body, a frangible closure below said chamber and adapted to be opened to admit well fluid toa low pres- 'sure chamber, suspension means on which said body is lowered inthe well, means at the lower end of said body for receiving and retaining a fish to be recovered, means operable by movement of said suspension means to open said closure and thereby induce a ilow. of well fluid into said chamber, and means on said body for maintaining a flow of circulation fluid downwardly through the suspension means and past said closure to the lower end of said body, the last mentioned means comprising a tube extending downwardly through said chamber, and means forming a iiuid passage communicating with said tube above said closure and with the interior. of said fish receiving means.

4. In a fishing tool of the character described, the combination comprising a body having upper and lower relatively vertically movable sections, a closure adapted to be opened to admit well fluid to a low pressure space within said upper body section, means at the lower end of said body for receiving and retaining a fish to be recovered, means operable by relative vertical movement of said body sections to open said closure and thereby induce a flow of well fluid into said chamber, and a. pipe surrounding said lower body section and conducting circulating fiuid from a passage within said upper body section into the interior of said fish receiving means.

5. In a fishing tool of the character described, the combination comprising a body having upper and lower relatively vertically movable sections, means forming a low pressure chamber within said upper body section, a closure within said upper body section adapted to be opened to admit well fluid to said low pressure chamber, closure opening means within said lower body section, a downwardly seating check valve above said closure acting to trap well fluid within said chamber, means at the lower end of said body for receiving and retaining a fish to be recovered, said closure opening means being operable by relative vertical movement of said body sections to open said closure and thereby induce a flow of well fluid into said chamber.

6. In a fishing tool of the character described, the combination comprising a. body having upper and lower relatively vertically movable sections, means forming a low pressure chamber within said upper body section, a closure adapted to be opened to admit well fiuid to said low pressure chamber, a. closure supporting member, means releasably holding said sections against relative vertical movement, means at the lower end of said body for receiving and retaining a. fish to be recovered, means operable by relative vertical movement of said body sections to open said closure and therebyinduce a flow of well iiuid into said chamber, and a check valve seating on said closure supporting member above the closure to trap well fluid within said chamber.

7. In a fishing tool of the character described, the combination comprising a body having upper and lower relatively vertically movable sections, means forming a low pressure chamber, interengaglng splines on said body sections, a closure adapted to be opened to admit well fiuid to said low pressure chamber, means at the lower end of said body for receiving and retaining a fish to be recovered, and means operable by relative vertical movement of said body sections to open said closure and thereby induce a fiow of well fluid into said chamber; and a downwardly seating check valve within said upper body section above said closure.

8. In a fishing tool of the characterl described, the combination comprising a body having a frangible disk closure adapted to be opened to admit well fiuid to a low pressure space, a tubular member supporting said disk, a check valve seating downwardly on said member above the disk, means at the lower end of said body and movable vertically relative thereto, for receiving and retaining a sh to be recovered, and means operable by straight relative vertical movementbetween the body and the last mentioned means to open said closure and thereby induce a ow of well fiuid into said space.

9. In a fishing tool of the character described, the combination comprising a body having upper and lower relatively vertically movable sections, a frangible disk closure adapted to be opened to admit well fluid to a low pressure space, a tubular member supporting said disk, a check valve seating downwardly on said member above the disk, means at the lower end of said lower body section for receiving and retaining a fish to be recovered, and disk breaking means operable* by relative vertical movement of said body sections to open said closure and thereby induce a fiow of well fluid through the lower body section in'to said space.

10. In a fishing tool of the character described, the combination comprising a body having'upper and lower relatively vertically movable sections, a closure adapted to be opened t admit well fluid to a low pressure space within said upper body section, means at the lower end of the lower body section for receiving and retaining a fish to 4be recovered, means holding said sections4 against relative rotation, means for opening said closure to draw a well fluid charge upwardly through the lower body section into said spaces by virtue of relative vertical movement between said body sections, and means for maintaining a downward circulation of uid past said closure to the lower end o! said lower body section.

11. In a fishing tool of the character described, the combination comprising a body having upper and lower relatively vertically 4movable sections, a closure adapted to be opened to admit well fluid to a low pressure space within said upper body section, means at the lower end of the. lower body section for. receiving and retaining a fish to be recovered, means holding said sections against relative rotation, means for opening said closure 'to draw a well uid charge upwardly through the lower body section into said space by virtue of relative vertical movement between said body sections, means for maintaining a downward circulation of uid past said closure to the lower end of said lower body section, and means for releasably holding the upper body sectionagainst 'downward movement relative tov the lower section.

12. In a fishing tool `of the character described, the combination comprising a body having an upper section containing a low pressure space, and a lower relatively vertically movable tubular section having a reduced diameter portion projecting upwardly into the upper section, a closure adapted to be opened to admit well fluid into said low pressure space, means holding said body sections against relative rotation, means operable by relative vertical movement between said sections to open said closure and thereby induce a ow of well uid upwardly through the lower body section into said low pressure space, means releasably holding the upper body section against downward movement relative tor the lower section.

WELDON C. ERWIN. 

